Injector won't fire

[Lance_S]

 

Green LED:

 

Off= no signal from the MAF.

Dim= Idle, Part throttle/Cruise.

On= MID

 

Unless I go out and pull my MAF- Translator cover and turn the ignition key to the on position...I can't tell you.

 

But I did read this in the installation instructions: When the vehicle is keyed-on, the two LEDs (Green and Red) in the Translator will turn on for appox. 1 second and then go back off.

 

Bill

 

 

Thanks Bill! OK, that is what it's doing. When i turn on the ignition, both lights will come on and then they will go out. I know that when the car is running, the green light will stay on, I just didn't know about when the ignition was on but not running. I thought my maft was bad but since I put the old unit back in and plugged it in and the car still wouldn't start I am beginning the maft is ok. I just don't know what that leaves.

 

Possibles?

Ingnitor?

fouled plugs, I will swap them out tomorrow.

Bad mas? I did clean mine before I put it back in with mas cleaner but I would hate to think that screwed it up.

Edited March 13, 2012 by Lance_S

[Lance_S]

You can hook a l.e.d. to injectors while they are connected to double check if actually firing

 

interesting. I guess if I put my timing light on the wire while it was turning over I could tell whether the fuel was being pulled out or the spark...I will give it a shot tomorrow.

 

Thanks Johnny

[StarquestRescue]

1 Get your cts hooked up if you did not all ready, so you have cold start enrichment.

2 Cam timing. dowel should be at about 11:58, not 11:50 like some one said.

3 Ignition timing.

4 If all else fails get out your compresssoin gauge. Did you bleed the lifters so they are not holding a valve open.

 

You are looking every where but where you had your fingers in the engine.

[Lance_S]

1 Get your cts hooked up if you did not all ready, so you have cold start enrichment.

2 Cam timing. dowel should be at about 11:58, not 11:50 like some one said.

3 Ignition timing.

4 If all else fails get out your compresssoin gauge. Did you bleed the lifters so they are not holding a valve open.

 

You are looking every where but where you had your fingers in the engine.

 

 

Yup, bled the lifters. Well, if your right then I am off cuz I was at 11:50. But Perry sent me a pic of his at TDC and his was in the exact same spot. I will see if i can post a pic for reference. They way I understand it is that the dowel is at 11:50 but the cam is at straight up 12:00. The dowel is offset a bit from the true straight up cam position.

 

My CTS is brand new and is hooked up.

 

I can do a quick compression test as well just to make sure everything is tight.

 

Thanks SQR.

[Ironside]

http://i1259.photobucket.com/albums/ii557/Ironsidestarion/0308120631.jpg

 

Is this wrong? I don't want to give wrong information.

[Lance_S]

that's the pic I was thinking of, thanks Ironside. That is what mine looks like as well. That, to me, is not 11:58, but after looking at a clock and comparing it, it's not 11:50, nor was mine. 11:55 maybe? I guess the whole point here is to make sure we are not a tooth off. I am going to pull the vc and take another look at it to make sure I am not off but if it's suppose to be straight up 12:00 then I am definitely a tooth off. And that would explain why she rolls over but doesn't run. It would also explain why I bent a valve on my last head, though it was over a 10,000 mile period.

[QuickMitz]

The pic looks wrong to me, the mating mark on the very outer edge of the gear should be at 3:00 and that would put the other mating mark at 11:58, there's a timing mark on the inside of the head that lines up with the outer mark.

[Lance_S]

It's correct. When the cam gear sits on the gear rest, it rotates counterclockwise a couple minutes. This is because the tensioner is on the left side of the chain. When the gear is on the cam, it should read straight up 12:00, but when it is pulled off the cam, it drops which allows the tensioner to pull on the chain from the left side which rotates it just a hair counterclockwise. So when the gear is on the rest it should be at 11:58, when the gear is on the cam, it should read 12:00.

 

Now I have pulled all of the plugs and cleaned them and checked them for spark and they are all fine. I have checked the motor for spark on the plug wires with the timing gun and #1 is firing continuously as long as I roll the motor over (5 seconds max). I have fuel pressure and have checked the injectors, they are firing. I have checked the timing and it is correct. Crank at tdc, cam dowel at 12:00 with the gear on the cam. I even pulled it off and jumped it a tooth and re-checked it just to make sure I wasn't off and I am not. I also checked the spark plug shoulder to make sure it was grounding out and all four of them are grounding out. I also re-gapped them to .040.

 

The only thing I can think of is that the fuel is getting pulled out after the first couple bursts. Either a bad ECU or maybe bad knock box. I will try Indy's suggestion of power to the knock box tomorrow.

 

Any ideas how fuel could be getting pulled out after the first couple bursts? Uggg. Frustrating.

 

L

[Tim_C.]

I would verify compression. A trained ear can tell if it is cranking with enough compression to start up and run. Otherwise, just put a gauge on it to see.

 

The engine must be on the compression stroke with the #1 piston all the way up (TDC), and cam dowel pin at 11:58. You don't have to see the pin to know if it is on the compression stroke. Just wad some tissue paper up and stick it in the #1 spark plug hole and bump the starter until you see the tissue paper blows out. Then take it the rest of the way to TDC on the crank by hand without going a full turn of course. Then check the rotor to make sure it is pointing to #1 with the adjustment in the center of the slot. I'm just wondering if maybe you don't have it on the compression stroke when putting the crank mark on TDC.

[Lance_S]

I would verify compression. A trained ear can tell if it is cranking with enough compression to start up and run. Otherwise, just put a gauge on it to see.

 

The engine must be on the compression stroke with the #1 piston all the way up (TDC), and cam dowel pin at 11:58. You don't have to see the pin to know if it is on the compression stroke. Just wad some tissue paper up and stick it in the #1 spark plug hole and bump the starter until you see the tissue paper blows out. Then take it the rest of the way to TDC on the crank by hand without going a full turn of course. Then check the rotor to make sure it is pointing to #1 with the adjustment in the center of the slot. I'm just wondering if maybe you don't have it on the compression stroke when putting the crank mark on TDC.

 

 

Thanks Tim.

 

I will give it a check tomorrow. I was going to pull the plugs and put a gauge on it to check but when I roll it over manually it sure feels like there is plenty of compression.

 

I am trying to think about this in my mind. Isn't it always on the compression stroke when the dowel is at 12:00? The motor strokes twice for every once one revolution of the cam gear. So the compression stroke is tied to the cam gear via the timing chain. The only way to be off of the compression stroke would be to have a dowel pin 180 degrees opposite the existing dowel pin wouldn't it?

 

The only other way to do what you say would be to lift up the timing chain and spin the gear 180 degrees from it's current position. And I didn't have the timing chain off the gear. I pulled the head but I didn't pull the timing chain so I don't see how I could be off a whole stoke. Correct me if I am wrong, I could be missing something. The motor was running with the proper timing when i pulled the head and I didn't change the timing chain at all. Just sent the head out for work, replaced the gasket, installed head studs and put it back together.

 

The only other thing I can think of is that I bought mas cleaner in a spray can. I cleaned the three inch gm mass before I reinstalled it. I wonder if the spray broke one of the little mas wires. If the ecu doesn't see air moving over the mas, it will pull the fuel. That would explain why it isn't starting. I know I have continuous spark so I am loosing my fuel. Unless of course, you are right and I am getting fuel in on the exhaust stroke and the fuel is just going in the cylinder and then out the exhaust and then the spark plug is firing with a dry cylinder.

 

I will check your compression theory tomorrow. Should be interesting. I don't know how it would be off 180 degrees on the cam gear but who knows at this point, I am stumped. I will try anything.

[Indiana]

You have spark and fuel and it sounds like you have the dist. in right. My vote goes to a lifter(s) that is holding valves open so it has no compression in some cylinders and it could be all of them if you didn't collapse them down and they were squishy when you put them back in. This is why I first check compression before I ever try and start it. I'd like to know what it is before and after its ran. It would start then die even if that MAS was dead. While cranking the injector pulse is at a fixed timed rate I don't know if even a MAFT changes that -I doubt it.

[wrngwae]

Lance,,,,, take a vid of it cranking......... we will know by the sound if it has compression.... you put new valves in that head right....... if so ... not trying to beat you up.... but you put the right ones in the rite place correct and if you did,,,,,,,, did you lap them???? if you have an air compressor and a compression gauge, most hook together. do a leak down test..... as in charge the cyl with air. that will push the piston down an hold it there. the valves should be closed at any down stroke. charge it with air and see if your loosing air out the exhaust or the intake. also check for blowby in the oil fill cap.... just trying to help brotha...

[Lance_S]

You have spark and fuel and it sounds like you have the dist. in right. My vote goes to a lifter(s) that is holding valves open so it has no compression in some cylinders and it could be all of them if you didn't collapse them down and they were squishy when you put them back in. This is why I first check compression before I ever try and start it. I'd like to know what it is before and after its ran. It would start then die even if that MAS was dead. While cranking the injector pulse is at a fixed timed rate I don't know if even a MAFT changes that -I doubt it.

 

 

I will do a compression test this afternoon as well as check with a timing light to make sure 2,3,and 4 are firing. I checked one but need to check the rest just to make sure. compression test next. I will post the numbers on a cold motor.

[Lance_S]

Lance,,,,, take a vid of it cranking......... we will know by the sound if it has compression.... you put new valves in that head right....... if so ... not trying to beat you up.... but you put the right ones in the rite place correct and if you did,,,,,,,, did you lap them???? if you have an air compressor and a compression gauge, most hook together. do a leak down test..... as in charge the cyl with air. that will push the piston down an hold it there. the valves should be closed at any down stroke. charge it with air and see if your loosing air out the exhaust or the intake. also check for blowby in the oil fill cap.... just trying to help brotha...

 

 

Thank brother.

 

The head was sent out and done by a professional. He decked the head, replaced the guides, did a 3 way seat job, ground for the larger intake (1mm SS larger valves) and installed the HD springs with new retainers. I am quite sure it was done properly as he has done hundreds of 2.6 heads. But of course, you never know. I am going to do a compression test, that will tell me if they are sealing properly. I also completely disassembled the rocker assembly, brake cleaned all the passages, buffed the rocker rails, finger sanded the inside of the rockers gently, cleaned them with brake cleaner, blew out all the oil passages and cleaned and purged the lifters with diesel fuel and relubed everything upon reassembly. They were nice and spongy when I installed them so they shouldn't be hanging a valve open but again....ya never know. Again, the compression test will tell me if I am getting a good seal or not. I will also do a tissue test on one to make sure I am on the compression stroke on the way up to tdc.

 

Crazy that she won't start. It will be really interesting when it does and I figure out what it is.

 

Thanks again for all the suggestions guys. We will get it figured out, but I wouldn't know what to do without you. Thanks. Lance

[Lance_S]

Well, I figured out what the problem is, now I am just not sure how to fix it. I put a compression tester on the head. All four cylinders are not holding pressure....all four of them. Sooooo, I pulled the vc and gave it a look. I didn't figure it was the head gasket so I looked toward the lifters. I knew they were squishy when I put them in so I didn't understand why they would be the problem but when I would roll the motor over so the valves were in the closed position I had zero play on the lifter. So I pulled them apart, re emptied them to make sure they were all getting squished down all the way and reinstalled them. The intake valves are still tight when closed. The exhaust valves actually have a little play when they are at the top. I can't lift the rocker off the top of the valve stem at all on any of the intake valves. So that explains it. What I don't under stand is why?

 

I am using a different rocker assembly than I was before so I measured the height of the towers and they are the same as the other towers on the old rocker assembly. I also measured the height of the actual cap that holds the lifter in place and it's the same height as the old one. The only thing I can think of is that the SS intake valves that I purchased from Dad are longer than stock and that is taking up my play. The head that I am running is a NJV clearwater head.

 

Anyone run into anything like this in the past? Totally confused as to how to fix this problem. I may mount the old rocker assembly just to make sure it's not the rockers but I doubt it.

[StarquestRescue]

Are they roller rockers? Was the head brand new or re maned. Maybe they cut the seats to deep for the o/s valves. Remember that the cam tower caps need to be the ones that came with the head. Although i do not think mismatch cam tower caps would keep the valves from closing.

[Lance_S]

Well. I had an extra set of rocker assemblies so I decided to put them on the car even tho i measured the towers and they were identical height I figured what the heck. Come to find out they work. I don't know what to say. There must be a difference between rocker assemblies. SQR, I am just running the stock hydraulic lifters and stock rocker assembly. I had two sets. One wouldn't let the Intake valves close all the way, the other one does. Like I said. I am stumped. But also glad to have solved the problem. I need to disassemble the rocker system, clean it out, blow all the oil passages clean and reassemble before a permanent install but I should have it done tomorrow. I will change the oil and filter and see If I can get it to fire up.

[Indiana]

Ya, you can't swap those caps you may have already ate the cam up and maybe the journals in the head too. If that's a regrind cam that could be the issue. Being a used head Vs new there may have been too much taken off the seats so the valves sit higher but there's lots of room for that in the lifters range and cutting the seat for OS valves doesn't much change the valve height. This also means you have unequal spring pressure on the valves exhaust to intake and if its off that way I'd question whether its off valve to valve. You'd have to measure the height off the top of the head to the retainer then maybe get shims to get them equal at least on one side. I think you're going to end up with mechanical rocker arms to make this work.

[Tim_C.]

Did you swap only the rockers, or rockers, lifters, shafts and cam caps? Try to narrow down what part it was that caused the problem of holding the valve open. It might help someone else to avoid this problem if you can figure out what and why, etc...

The lifters have about .120 of travel measured when fully extended compared to fully compressed (squished). This allows for slightly different valve heights, cam base, and overall placement of the cam in the caps.

I'm curious about the cam like Indiana mentioned, but you kept that in with no problems on the 2nd set of parts. Really odd one for sure.

Every OEM Mitsu lifter preload I've seen has been way on the loose side. My machinist didn't like how loose it was, so we tightened up the spec considerably. OEM is usually around .015 of lifter travel on the back side of the cam, off of the lobe. We tightened mine up to .065 with no problems. That is over half of the travel.

Did you check the spring tension? It should be a minimal of 65 Lbs at the seat fully closed. I've never seen a used spring over 55 lbs and that was on a 75K mile motor. Most are around 50 Lbs. HD springs are 100 Lbs new, but lose 10 Lbs after the first hour of run time or so. I like to shim them so they stay up around 100 when broke in (for lack of a better term).

 

Well, I'm glad the new set-up seems to be working. I'd like to hear how it works out when you go to start it up again.

[StarquestRescue]

Perhaps the one set of rockers and shafts are badly worn and are giving the extra clearance. Can you post pictures of the rockers? Do both sets of intake rockers have the ear for the jet valve adjuster?

[Lance_S]

Yup, both sets have the ear. The NJV head wasn't new so when I received it I couldn't match the towers up to the head. Both sets would not have matched up perfectly as neither of them came with the head. The head had a small warp to it, most likely from overheating at some point in it's life, but it was decked to correct the offset. The cam isn't a regrind, it's completely stock as far as I know. I can pull it and measure it since I have to pull the towers for cleaning anyway. I will pull the fsm, take measurements to let you know whether the cam was cleaned up or not. It's the original cam i ran on my last head but again, I am not sure if it was reground or not without taking measurements. I actually sent the head guy two cams and he measured them both and instructed me to use the one that is in there now so I am assuming the one that I have is closest to stock measurements. The motor is a fresh rebuild with 10K miles on it. The springs are brand new HD springs. I didn't think about shimming them. I certainly could do that but don't know where to get the proper shims for that. Let me know if you have an idea. But even if they loose 10 percent they are still pulling 90 lbs of seat pressure at rest which is way more than stock. I certainly noticed a difference when I first switched to them.

 

I had two compete sets of rockers including the towers, shafts, rockers and caps. I cleaned the set that came with the head and used that one since I figured it was mated to it. But alas, that was the one that wasn't giving me the clearance I needed so I put on my old assembly and it worked. Like you said, it might just be a slight wearing issue that is causing more clearance.

 

One thing is for sure. We are dealing with 25 year old equipment. I don't know how many miles are on either rig. I don't know what the wear is on the wear pads themselves or whether there was a change in the manufacturing specs along the way somewhere. I just know that one set of towers works, the other one doesn't. I used plenty of assembly lube on the original build so I am not worried about the cam at this point, I am sure it's fine but will mic some measurements on the journals and lobes when I pull it and compare it to the fsm and post what I find. I certainly don't have the travel that I used to but I am closing on all the valves so that is the important thing. The rest will be taken up by the lifter when it gets pumped up.

 

SQR, I can take pics and some measurements to see where I am off. I also have two sets of lifters and switched those as well, maybe the old lifters that I put back in had additional squish to them that the first set didn't. I am just glad I figured it out. I have been chasing this for a while.

 

I am guessing that when the head was redecked and the valve job was done it set the valves slightly deeper in the head. That would explain why the top of the valve is a few thousanths higher than it was originally. Randy said the SS valves are the same height as the stockers so there shouldn't be a difference there. When the machinist opened the intake valve for the extra 1mm he might have allowed it to go a little deeper, this head has about 20 hours of port work on it so the seats might have been a hair deeper than the stock head which is lifting the valve stem up a bit. That is logically the only thing I can think of that is different. But, of course, it's also a different casting (clearwater njv) so honestly we aren't even talking apples to apples from my stock head to this one. Either way, just glad I am making progress. Interesting case to say the least. Thanks guys for all the ideas and help. I will post the results.

 

Sincerely,

 

Lance

[Tim_C.]

Not sure if I am reading correctly, but you must use the cam towers that came with the head. Those cannot be swapped head to head as they will not be perfectly round. They are bored in the head. Do not use a different set of towers or the cam journals can get eaten up. Swap the rockers and shafts from one set of towers to another, but not the towers from head to head.

The springs are fine for a stock cam. No need for shims.

A warped head cannot be straightened by decking. It isn't just the mating surfce that gets warped, but the entire head. It must be heated in an oven and straightened before being surfaced. I'm sure your experienced machinist knows and did it correctly if it was warped.

I have seen a clearwater head that had to use mechanical rockers to work. The hydraulic lifters would hold the valves open like yours is. This was about 7 years ago and I didn't remember until now. Some castings will only work with mech rockers.

 

I still don't understand how your machinist would have given the head back to you like that. All of this stuff is standard to be checked on any hydraulic set up. It couldn't have been holding the valves open when he assembled it. So it must have only started to hold them open after the lifters pumped up, which means the relationship between the hydraulic rocker shaft assembly and the head cast is wrong. Still, he should have seen it was going to hold the valves open if the lifters get fully pumped up. I wouldn't rely on the 'working for now', set up. I would put mechs on it if I were you.

[Lance_S]

He sent me the head with the rockers out of it, just the head, springs, and retainers. I installed the rocker assembly. I will know more when I get it together tomorrow and have had time to take all the measurements.

[Lance_S]

I am planning on swapping the rockers off the old setup onto the caps that are for the new head, hopefully that will give me what I need.

 

L

[Lance_S]

I swapped out the caps and rebuilt the rocker assembly, put it on and I have compression on all 4 cylinders. The lifters aren't pumped up yet because I haven't run it yet but I did a quick compression test on all 4 and I have 127 on 1 and 2, and 120 on 3 and 4 on a cold motor. I purchased a new cam cap but didn't want to install it till I confirmed compression. I am still not 100% sure what the difference in rockers is. I measured the lifter openings and they appear to be the same as the other set. The pads on the rockers look good too. But I didn't want to spend the whole day measuring the differences, I was just anxious to put it together and see if it worked. I did spend quite a bit of time cleaning all of the surfaces and making sure all of the oil passages were clean.

 

I will finish up the little things tomorrow and get it running. Thanks again to everyone for your help.

 

L